Fan construction



Aug. 27, 1 B. STEVENS, -JR

FAN CONSTRUCTION Filed Jan. 20, 1938 172016752707 Peaks" (5260876 79:

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Patented Au 27, 1940 UNITED STATES PATENT OFFICE FAN CONSTRUCTION poration of Maine Application January 20, 1938, Serial No. 185,877

16 Claims.

This invention relates to an improved electric fan construction and to an improved reinforcement for electric fans, particularly electric fans which have flexible blades formed of rubber or the like.

A fan of this type is commonly provided with a fixed casing to contain the motor and with a rotatable nose disposed at the end of the easing, the rubber blades being fixed to and extending from the rotatable nose. The latter may be of conoidal form, so that the fan has a so-called stream-lined shape. The motor shaft extends into the nose and is commonly secured to the mid-portion thereof at a substantial distance from the bearing at the nearer end of the motor.

Thus the nose is supported by a rather long projecting shaft portion, which heretofore has not been suitably reinforced. As a consequence when a fan of this type received an accidental blow, as

for example, by being dropped onto the floor,

the nose portion of the fan was likely to be displaced and the shaft sprung so that the fan would no longer operate properly.

The present invention affords a reinforcement for the nose and projecting shaft portion of such a fan so that these parts of the fan can withstand substantially heavier blows than could heretofore have been received without adversely affecting the operation of the fan. To permit this desirable result as well as to afford certain additional advantages, I preferably provide a reinforcing member having a sleeve to surround the shaft extension. The bore of the sleeve may be provided with an integrally threaded end portion 5 for connection to the center of the nose by a single screw. The reinforcement also preferably includes a plurality of substantially planar, radially disposed strut elements. These elements may be arranged so that when the screw is tightened their outer surfaces are pressed against the yieldable material of the inner parts of the fan blades, thus to afford a yieldable support for the adjoining parts of the nose. The reinforcement also preferably is provided with a reinforcing ring for the periphery of the nose, which is juxtaposed to the motor casing, this ring being connected to the outer parts of the strut elements. at least a portion thereof projects slightly beyond the surface of the nose and the adjoining surface of the casing, thus in effect affording a cylindrical bead for this portion of the assembly.

A further advantage of the reinforcement may be realized if suitable openings are provided in 5 the rotatable nose and cooperating openings are Preferably the ring is arranged so that provided in the motor casing. Under such con ditions, the strut elements of this reinforcement may function as the blades of a centrifugal fan to cause the circulation of air through the openings provided in the nose and fan casing, thus 6 permitting effective cooling of the fan motor.

In the accompanying drawing:

Fig. l is a front elevation of the nose of a fan having flexible blades with certain of the blades removed; 10

Fig. 2 is a side elevation of a fan having a nose such as shown in Fig. 1, the nose assembly and related parts being shown in section;

Fig. 3 is a front elevation of the reinforcement member employed in the nose assembly as shown 15 in Fig. 2;

Fig. 4 is a side elevation of the reinforcement; and i Fig. 5 is a section on line 55 of Fig. 4.

The principles of the invention may be em- 20 ployed to particular advantage with a fan having flexible blades I, formed of rubber or the like material and secured to a nose 2 which may have the general form of a conoid and which may conveniently be stamped of sheet material. The 25 blades may extend through curved slots 5 in the nose 2 and have inner portions 3 disposed upon the inner side of the sheet metal of the nose 2. The periphery of the nose 2 may have substantially the same diameter as that of the fixed ca- 30 ing 6 which encloses the motor of the fan. This motor includes a rotor 1 which may comprise'the conventional armature and armature shaft. The latter is provided with an extension 8 which projects into the nose 2. The casing 6 provides a 35 hearing 9 for the shaft, as shown in dotted lines in Fig. 2, this bearing being substantially in the plane of the periphery of the nose 2.

It is evident that, due to the shape of the nose 2, there is a substantial distance between the 40 bearing 9 and the center of the nose. Thus an overhanging assembly of substantial length is afforded, which is particularly likely to be distorted when the nose of the fan is subjected to a rather heavy blow. To reinforce this portion of the fan, i. e., the shaft extension 8 and the nose 2, I preferably provide a novel reinforcement which more specifically forms the subject matter of the present invention.

This reinforcement may be in the form of a 50 metal member 20 which includes a sleeve 2| enclosing the major part of the shaft extension 8. The opposite end of this sleeve is provided with an internally threaded bore to receive the shank of a screw 22 which secures the midportion of the nose of the reinforcement 20. The latter may also include a plurality of integral strut elements 24 having planar body portions reinforced by outer ribs 25. These ribs define the outer edges of the struts and incline away from the center of the reinforcement preferably gin of the nose and supporting a reinforcing ring I 29. This ring may provide an external annular bead which may act as a stop to limit the movement of the edge of the sheet metal nose when the screw 22 is tightened. This bead 30 preferably projects slighthr beyond the outer surface of the peripheral portion of the nose and the corresponding portion of the motor casing 6, thus affording a finished appearance for the joint between the rotatable nose assembly and the fixed motor casing.

Obviously when the screw 22 is tightened, the ribs 25 at the outer edges of the strut elements 24 are pressed against the surfaces of the inner parts 3 of the rubber blades I, thus yieldably supporting portions of the sheet metal of the nose 2 intermediate its mid-portion and its peripheral portion. The ring 29 is provided with a surface which engages the inner marginal surface portion of the sheet metal nose 2, thus to afford a reinforcement and support for this part of the nose, it being evident that the general stillness of this part of the assembly is also enhanced by the head 30.

Due to the arrangement of the sleeve 2|, the overhangin Portion of the shaft is reinforced and stiffened for the major portion of its length so that there is substantially less likelihood of the shaft being sprung, if the nose portion of the fan is subjected to a severe strain. Thus shocks imparted tothe sheet metal of the nose portion are absorbed in a considerable measure by the reinforcement 20, and may be transmitted through the same to the short section of the shaft 8 between the reinforcement and the bearing 9.

Obviously the reinforcement 20 afiords a substantial stiffening effect for the peripheral portion of the nose 2 as well as affording a reinforcement for parts of the nose 2 adjoining the inner parts 3 of the rubber blades. Since the inner margin of the strut elements are much closer to the bearing 9 than to the mid-portion of the nose, thus parts of the elements afford. effective strut-like reinforcements between the periphery of the nose and the shaft extension in the region of the bearing assembly 9.

Preferably the reinforcement 20 may be detachably secured to the projecting shaft portion.

8 by a set screw 39 or the like Fig. 3. The reinforcement may be formed in a plurality of pieces but preferably may be a single integral part, such as a forging, or preferably a casting.

A further advantage of my improved remforcement may be realized if suitable openings such as the openings are provided in the sheet metal nose 2 and cooperating openings are provided in the casing 6, as for example, openings 26 in the end wall of the casing adjoining the nose and openings 31 in the opposite end of the casing. When openings are provided in the nose and the motor casing in this manner, the strut elements 20 can function as the impellers of a centrifugal fan so that air may be drawn instruts engaging the yieldable inner portions of the blades, thereby reinforcing the adjoining portions of the nose and preventing inward move ment of the blades.

I claim:

1. Electric fan of the class described comprising a motor casing, a rotatable conoidal nose at the end of said casing, blades extending from said nose, a rotor within said casing, said rotor .including a shaft extension projecting into the nose and secured to the mid-portion thereof, said casing being provided with a bearing for the shaft, and a reinforcement for the nose and shaft extension, said reinforcement providing a sleeve around said extension and providing a ring reinforcing the periphery of the nose adjoining the casing.

2. Electric fan of the class described comprising a motor casing,'a rotatable conoidal nose at the end of said casing, flexible blades extending from said nose, a rotor within said casing, said rotor including a shaft with a portion projecting into the nose and secured thereto, said casing being provided with a bearing for the shaft, and a reinforcement for the nose and projecting shaft portion, v said reinforcement including a sleeve around said portion and strut elements extending outwardly from said sleeve, said blades having yieldable inner parts disposed within the nose, the outer portion of said elements engaging said parts of the blades, thereby preventing inward movement thereof.

3. Electric fan of the class described comprising a motor casing, a rotatable conoidal nose at the .end of said casing, flexible blades extending from said nose, a rotor within said casing, said rotor including a shaft with a portion projecting into the nose and secured thereto, said casing being provided with a bearing for the shaft, and a reinforcement for the nose and projecting shaft portion, said reinforcement providing a sleeve around said portion, strut elements extending outwardly from the said sleeve, and a reinforcing ring for the edge of the nose which adjoins the casing.

4. Electric fan of the class described comprising a motor casing, a rotatable conoidal nose at the end of said casing, flexible blades extending from said nose, a rotor within said casing, said rotor including a shaft with a portion projecting into the nose and secured thereto, said casing being provided with a bearing for the shaft, and a reinforcement for the nose and projecting shaft portion, said reinforcement providing a sleeve around said portion, and strut elements extending outwardly from said sleeve, said blades having inner parts disposed within the nose, the outer portions of said elements enga ing said parts of the blades, and a reinforcing ring for the edge oi the nose adjoining the casing, said elements supporting said ring, said ring providing an annular bead at the edge of the nose adjoining the casing.

5. Electric fan of the class described comprising a motor casing, a rotatable conoidal nose at the end of said casing, flexible blades extending from said nose, a rotor within said casing, said rotor including a shaft with a portion projecting into the nose and secured thereto, said casing being provided within a bearing for the shaft, and a reinforcement for the nose and projecting shaft portion, said reinforcement providing a sleeve around said portion and strut elements extending outwardly from said sleeve, said blades having inner parts disposed within the nose, the outer portions of said elements engaging said parts of the blades.

6. Electric fan of the class described comprising a motor casing, a rotatable conoidal nose at the end of said casing, blades extending from said nose, a rotor within said casing, said rotor including a shaft with a portion projecting into the noseand secured thereto, said casing being provided with a bearing for the shaft, and a reinforcement for the nose and projecting shaft portion, said member providing a sleeve around said portion and strut elements extending outwardly from said sleeves, said nose having openings therein and said casing also providing openings, the strut elements acting as air impellers to cause the circulation of air through the openings, whereby the motor may be effectively cooled.

7. A reinforcing member for the nose assembly of a fan, comprising a sleeve for surrounding a projecting portion of a rotatable shaft, said sleeve having an internally threaded end, a plurality of substantially planar strut elements extending in radial planes from said sleeve, said elements having inner and outer edges with general inclinations away from the threaded end of the sleeve, the inner and outer edges of each element extending toward each other, and a ring connected to the outer parts of said elements, said ring being disposed to rotate about a part of said shaft which is spaced farther from said threaded end 1 of the sleeve than is the opposite end of the sleeve.

8. Electric fan of the class described comprising a motor casing, a rotatable conoidal nose at the end of said casing, flexible blades extending from said nose, a rotor within said casing, said rotor including a shaft with a portion extending into the nose and secured to the mid-portion thereof, said casing being provided with a bearing for the shaft, and a reinforcement for the nose and projecting shaft portion, said reinforcement providing a ring reinforcing the periphery of the nose, said ring providing an annular bead at the edge of the nose adjoining the end of the casing.

9. Electric fan comprising a motor having a fixed, generally cylindrical casing and including a rotor with a projecting shaft portion, a round nose reinforcement secured to said shaft portion and providing a peripheral bead juxtaposed to the end of the casing, said bead having a slightly greater diameter than the adjoining end of the casing, and a conoidal metal nose member fitting over the nose reinforcement and having a peripheral portion juxtaposed to said head, said lastnamed portion having a diameter substantially equal to that of the adjoining end of the motor casing.

10. Electric fan of the class described comprising a motor casing, a rotatable conoidal nose at the end of said casing, said nose having a periphery adjoining the end of the casing, flexible blades extending from said nose, a rotor within the casing, said rotor including a shaft with a portion projecting into the nose and secured thereto, said casing being provided with a bearing for the shaft, and a reinforcement for the nose and projecting shaft portion, said nose fitting over said reinforcement and being removable therefrom, the reinforcement including a sleeve on said shaft portion and strut elements extending for the major portion of the length of the sleeve, said reinforcement providing regions of support at the ends of the strut elements for the periphery of the nose.

11. Electric fan of the class described comprising a motor casing, a rotatable conoidal nose at the end of the casing, said nose having a periphery adjoining the end of the casing, flexible blades extending from said nose, a rotor within the casing, said rotor including a shaft, said casing being provided with a bearing for the shaft, the shaft having a portion projecting beyond the bearing, and a reinforcement for the nose secured to said shaft portion, said reinforcement providing a substantially continuous circumferential surface supporting the periphery of the nose adjoining the casing.

12. Electric fan of the class described comprising a motor casing, a removable rotatable assembly at the end of said casing, said assembly including a conoidal nose, said nose having a periphery juxtaposed to the end of the casing, said assembly also including flexible blades extending from said nose, a rotor within the casing, said rotor including a shaft with a portion projecting into the nose and secured thereto, said casing being provided with a bearing for the shaft, and a reinforcement for the nose and projecting shaft portion, said assembly fitting over said reinforcement and being., removable therefrom, the reinforcement including a sleeve onsaid shaft portion, and strut elements disposed in substantially radial planes and extending for the major portion of the length of the sleeve, the outer portions of said strut elements providing regions of support for the removable assembly.

13. A fan comprising a hub member, webs projec'ting from said hub member so as to form a spider, a shell concentrically supported on said spider at one end of said webs and extending over said spider with space between the top of said webs and said shell, said shell having openings therethrough, fan blades projecting through said openings in said shell and means provided on the base of said blades within the space between the top of the webs and the inside of said shell to support said shell on said spider and hold said blades locked to said shell.

14. In a fan, a hub member, an inner supporting member carried on said hub member and having peripheral surface portions which lie substantially on a surface of revolution which is approximately conical, a shell closed at one end and surrounding said supporting member and being carried, on said hub member substantially concentric with and parallel to said supporting member and being spaced therefrom and further being provided with slots, blades respectively adapted to be received in said slots, said blades being provided with base shoulder portions adapted to fit between and engage said shell and said supporting member, whereby said shell is supported on said supporting member by said shoulder portions.

15. In a fan, a hub member, an inner supporting member carried on said hub member and having peripheral surface portions which lie substantially on a surface of revolution which is approximately conical, a shell closed at one end and surrounding said supporting member and being carried on said hub member substantially concentric with and parallel to said supporting member and being spaced therefrom and further being provided with slots, blades respectively adapted to be received in said slots, said supporting member being provided with a terminal flange agai st which the open end of said shell abuts,

said'blades being provided with base shoulder porti ns adaptedto fit between and engage said shell and said supporting member, whereby said shell is supported on said supporting member by said shoulder portions.

16. In a fan, a hub member, a supporting mem- 

